Development of a GPU-based multithreaded software application to calculate digitally reconstructed radiographs for radiotherapy.

To provide faster calculation of digitally reconstructed radiographs (DRRs) in patient-positioning verification, we developed and evaluated a graphic processing unit (GPU)-based DRR software application and compared it with a central processing unit (CPU)-based application. The evaluation metrics were calculation speed and image quality for various slice thicknesses. The results showed that the GPU-based DRR computation was an average of 50 times faster than the CPU-based methodology, whereas the image quality was very similar. This excellent performance may increase the accuracy of patient positioning and improve the patient treatment throughput time.